diff --git a/src/scripts/find-successful-workflow.js b/src/scripts/find-successful-workflow.js
index d003497..e0d526b 100644
--- a/src/scripts/find-successful-workflow.js
+++ b/src/scripts/find-successful-workflow.js
@@ -3,7 +3,7 @@ const { execSync } = require('child_process');
 const https = require('https');
 
 const buildUrl = process.argv[2];
-const pullRequestUrl = process.argv[3];
+const branchName = process.argv[3];
 const mainBranchName = process.env.MAIN_BRANCH_NAME || process.argv[4];
 const errorOnNoSuccessfulWorkflow = process.argv[5] === '1';
 const allowOnHoldWorkflow = process.argv[6] === '1';
@@ -14,7 +14,7 @@ const [, host, project] = buildUrl.match(/https?:\/\/([^\/]+)\/(.*)\/\d+/);
 
 let BASE_SHA;
 (async () => {
-  if (pullRequestUrl) {
+  if (branchName !== mainBranchName) {
     BASE_SHA = execSync(`git merge-base origin/${mainBranchName} HEAD`, { encoding: 'utf-8' });
   } else {
     try {
diff --git a/src/scripts/set-shas.sh b/src/scripts/set-shas.sh
index 6b79ac1..c16850c 100644
--- a/src/scripts/set-shas.sh
+++ b/src/scripts/set-shas.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 echo "$PARAM_SCRIPT" >>"index.js"
-RESPONSE=$(node index.js $CIRCLE_BUILD_URL $CIRCLE_PULL_REQUEST $PARAM_MAIN_BRANCH $PARAM_ERROR_ON_NO_SUCCESSFUL_WORKFLOW $PARAM_ALLOW_ON_HOLD $PARAM_WORKFLOW_NAME)
+RESPONSE=$(node index.js $CIRCLE_BUILD_URL $CIRCLE_BRANCH $PARAM_MAIN_BRANCH $PARAM_ERROR_ON_NO_SUCCESSFUL_WORKFLOW $PARAM_ALLOW_ON_HOLD $PARAM_WORKFLOW_NAME)
 echo "$RESPONSE"
 BASE_SHA=$(echo "$RESPONSE" | grep 'Commit:' | sed 's/.*Commit: //')
 HEAD_SHA=$(git rev-parse HEAD)